From Gene To Protein (I/ii)

Front 1

____ is the bridge between genes and the proteins for which they code

Back 1

RNA

Front 2

__________ is the synthesis of RNA using information in DNA, producing mRNA. ________ is the synthesis of a polypeptide using information in the mRNA.

Back 2

Transcription; Translation

Front 3

Where is the site of translation?

Back 3

Ribosome

Front 4

__________ translation of mRNA can begin before transcription has finished while _________ RNA transcripts are modified through RNA processing to yield finished mRNA.

Back 4

Prokaryotic; Eukaryotic

Front 5

A _________ code of nucleotides corresponds to an AA, which are transcribed into ____________ mRNA and then translated into a chain of ___________.

Back 5

triplet code; complimentary; polypeptides

Front 6

In which direction are mRNA base triplets read?

Back 6

5' to 3' direction

Front 7

One of the two DNA strands, provides atemplate for ordering the sequence ofcomplementary nucleotides in an RNAtranscript, which is called the ________.

Back 7

template strand

Front 8

The genetic code is _________, where more than one codon may specifya particular amino acid, but not ___________, where no codon specifies more than oneamino acid

Back 8

redundant; ambiguous

Front 9

RNA synthesis is catalyzed by _________, which pries the DNA strand apart/untwists it and hooks the RNA nucleotides together. The DNA sequence where RNA polymerase attaches is called the ___________, which signals the transcriptional start point.

Back 9

RNA polymerase; promoter

Front 10

In bacteria, the sequence signaling theend of transcription is called the ___________.

Back 10

terminator

Front 11

____________ mediate the binding of RNA polymeraseand the initiation of transcription. ____________ is the completed assembly of transcriptionfactors and RNA polymerase II, which bound to a _________

Back 11

Transcription factors; Transcription initiation complex; promoter

Front 12

The _________ is a promotor which is crucial in forming the initiation complex in eukaryotes.

Back 12

TATA Box

Front 13

Nucleotides are added to the _______ end of the growing RNA molecule

Back 13

3' end

Front 14

What's the difference between bacteria and eukaryotes in terms of "Termination of Transcription"?

Back 14

-In bacteria– the polymerase stops transcription atthe end of the terminator– the mRNA can be translated withoutfurther modification

-In eukaryotes– RNA polymerase II transcribes thepolyadenylation signal sequence– the RNA transcript is released 10–35nucleotides past this polyadenylationsequence

Front 15

Modification of RNA after Eukaryotic transcription- 5'/3'

Back 15

5' end: recieves a modified nucleotide 5' cap

3' end: gets a poly-A Tail

Front 16

What's the purpose of the 5' cap/ poly-A Tail?

Back 16

– facilitate the export of mRNA to the cytoplasm

– protect mRNA from hydrolytic enzymes

– help ribosomes attach to the 5' end

Front 17

Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that lie between coding regions called intervening sequences, or _________. The other regions, called _______, are eventually expressed and translated into amino acid sequences.

Back 17

introns; exons

Front 18

__________ removes introns and joins exons, creating an mRNA molecule with a continuous coding sequence.

Back 18

RNA splicing

Front 19

RNA splicing is carried out by _________, which consists of _____________, which recognize splice sites. _____________ are catalytic RNA molecules that function as enzymes which can also splice RNA.

Back 19

small nuclear ribonucleoproteins (snRNPs); ribozymes

Front 20

mRNA is created into proteins through a process called ______. This occurs through _________, which moves AA's to the growing polypeptide in a ribosome.

Back 20

Translation; transfer RNA (tRNA)

Front 21

tRNA is roughly ____-shaped, with a single RNA strand attached that looks like a ________. tRNA twists/ folds into a 3-D molecule because of _________. Each tRNA carries a specific amino acid on one end.

Back 21

L-shaped; cloverleaf; H-bonding

Front 22

What are the 2 steps of accurate translation?

Back 22

1) a correct match between tRNA and an AA via the ezynme aminoacyl-tRNA synthetase

2) a correct match between the tRNA anticodon and an mRNA codon

Front 23

A ________ refers to the flexible pairing at the 3rd base of a codon, which allows some tRNAs to bind to more than 1 codon

Back 23

Wobbles

Front 24

Which enzyme allows the correct match between tRNA and an AA?

Back 24

aminoacyl-tRNA synthetase

Front 25

Ribosomes facilitate specific coupling of tRNA anticodons with mRNA codons in protein synthesis. What are the 3 binding sites for tRNA on a ribosome? What do they do?

Back 25

1) P-Site- holds tRNA carrying growing PP

2) A-Site- holds tRNA carrying next AA being added

3) E-Site- exit site. where tRNA is discharged

Front 26

What are the 3 stages of translation?

Back 26

1) Initiation

2) Elongation

3) Termination

Front 27

A number of ribosomes can translate a single mRNA simultaneously, forming a ___________, which enable a cell to make many copies of a polypeptide very quickly.

Back 27

polyribosome (polysome)

Front 28

What's the difference between free & bound ribosomes?

Back 28

– free ribsomes: in the cytosol and are mostly synthesize proteins that function in the cytosol

– bound ribosomes: attached to the ER, make proteins of the endomembrane system, and proteins that are secreted from the cell

Front 29

Polypeptides destined for the ER or for secretion are marked by a ____________.

Back 29

signal peptide

Front 30

A ________, which binds to the signal peptide, brings the signal peptide and its ribosome to the ER.

Back 30

signal-recognition particle (SRP)

Front 31

______________ are chemical changes in just one base pair of a gene, such as in Sickle-cell hemoglobin, where Glu is converted into Val.

Back 31

point mutations

Front 32

Silent vs Missense vs Nonsense Mutation

Back 32

1) Silent Mutation- have no effect on the amino acid produced by a codon because of redundancy in the genetic code.

2) Missense Mutation- still code for an AA, but not the correct AA

3) Nonsense Mutation- an AA codon converted into a stop codon, which leads to a nonfunctional protein

Front 33

What are 2 different types of point mutations?

Back 33

1) nucleotide-pair substitutions (Silent/ missense/ nonsense mutation)

2) insertions or deletions

Front 34

__________ are physical/ chemical agents that can cause mutations.

Back 34

Mutagens

Front 35

Insertions/ deletions are additions or losses of nucleotide pairs in a gene that may produce a _____________, which effects the following nucleotides.

Back 35

frameshift mutation

Front 36

Elongation of a PP chain proceeds along the mRNA in a ___________ direction. Each AA addition involves _________, which occurs in 3 steps: codon recognition, peptide bond formation & translocation. AA's are added one-by-one at the ___________ of the growing chain.

Back 36

5' to 3' direction; elongation factors; C-terminus

Front 37

Termination of translation occurs when a stop codon in the mRNA reach the _________ of the ribosome, which accepts a protein called a __________ that causes the addition of a H2O molecule instead of an AA. This reaction releases the polypeptide.

Back 37

A Site; release factor